AFP in maternal serum

Rate: Rs. 600

Sample

Pregnant mother serum is needed.It is stable for 24 hours at 2-8 C.

Important facts

• AFP is synthesised in liver and some of the fetal AFP enters the maternal serum.
• Maternal serum reaches at its peak at 30th week of gestation, then declines rapidly to <2% of the maximum level by 34-36 weeksof pregnancy.

Normal

• 14 week of gestation = 25.6 ng/ml ( median)
• 16 week of gestation = 34-8 ng/ml( median)
• 18 week of gestation = 47.3 ng/ml (median)
• 20 week of gestation = 64.3 ng/ml (median)
• 21 week og gestation = 74.9 ng/ml (medial)

Raised level

• Maternal serum level >2 times the median level will be seen in:
1. Multiple gestation.
2. Fetal death.
3. Malformations e.g.enencaphaly.
4. Increased AFP concentration in maternal serum and amniotic fliud is seen in:
   1. open neural tube defects like anencephaly, spina bifida, omphalocele, oesophageal or doudenal atresia.

Decreased maternal serum is seen

1. Down syndrome (Trisomy 21).
2. Molar pregnancy.
3. Spontaneos abortion.
4. overestimated gestational age.